Insulating composition and process of making the same.



ing the Same,

- whether fired CHARLES P. STEINLIETZ, OF SCHENECTADY,

NEW YORK, ASS IGNOR TO GENERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

INSULATING COMPOSITION AND PROCESS OF MAKING THE SAME.

No Drawing.

To all whom it may concern.

Be it known that I, CHARLES P. STEIN- ME'rz, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and usefullmprovements in -Insulat ing Compositions and the Process of Makof which the following is a specification.

My invention relates to compositions suitable for electrical insulation, especially where it is important that the composition shall be heat resistive.

The object of my invention is to provide a cheap and eflicient material which can be readily molded and machined into desired form. In accordance with said invention a refractory earthy compound such as talc,

silica, alumina and the like is mixed in pow-- dered form with a binder consisting of a gelatinous compound of substantially the same composition. The. mixture is sha ed into desired form, as by molding or squirting, and is finally fired.

As an example of my invention, I will describe the production of an artificial or reconstructed lava Soapstone or talc chemically is a hydrated silicate of magnesia. When fired it gives up vwater of hydration and results in a hard, stony mass known as lava in the electrical for any reason, have heretofore been a total loss. I can utilize either the fired material or waste from the process of machining the natural soapstone, which heretofore has been extremely large, but .prefer to use in my new composition at least some'unfired ta 0. The powdered magnesium silicate or unfired ,or a mixture of both is thoroughl mixedwith agelatinous, or colloidal, bin er: of magnesium silicate, asmuch of thecolloidal binder being added as is necessary 'to make the mixture easily moldable and to thoroughly fill all the "spaces between .the talc particles. The

ared by precipitating a solution of magnesium' salt, such as the su1-'- bmder-may be prep Specification of Letters Patent.

Application filed July 29, 1911. SeriaINo. 641,220.

'the usual way ,silica may be molded with a binder molded, dried and Patented Dec. 31,1912.

fate of magnesium, such as sodium silicate. The flocculent, gelatinous precipitate is conveniently separated by means of a centrifugal separator from the solution and carefully washed free from soluble salts, for exam le in the'casegiven, free from sodium sul at'e. The gelatinous precipitate has a large and varying percentage of water of hydration and, therefore, exact proportions cannot be given.

' The mixture may be molded in the usual way, or it may be squirted in the form of rods or tubes and after drying machined in a lathe or otherwise much like a piece of native talc. sired form and thoroughly dried the articles are fired in the same manner as articles formed from native talc are fired, as in an ordinary porcelain kiln at a temperature of 10001300' O. or even higher.

Articles made according to this process are cheaper than when made from natural lava and when 0 rated in heating devices, in places where tliiiy are exposed to arcsfor, under other trying conditions have a life equal to the best grade of natural lava.- In a similar manner I can make articles consisting of a filler of powdered alumina and a binder of gelatinous aluminum hydroxid. The latter compound can be precipltated in by adding an alkaline. hydroxid or carbonate to a solution of an aluminum compound. Similarly, a filler of of gelatinous silica, precipitated by adding an acid to a soluble silicate,

Centrifugal separation can be conveniently These materials are fired as already deused in each case.

scribed.

What I claimas new and desir to secure by Letters Patent of the United tes, is,

1. Th powdered ta 0 with gelatinous magnesium silicate, moldmg the mixture under pressure and firing at anelevated temperature. 2. The process which co powdered tale with a gelatmous magnesium After being shaped lnto de-' nsists in mixing with a soluble silicate,

such as sodium silicate.

e process which consists in mixing sure and firing at a temperature at or about 3. A machineable, consisting of mineral talc and. a binder of precipitated gelatinous magnesium silicate, and convertible by firing to a material having the heat resistin properties of natural ava.

molded artificial lava In witness whereof, I have hereunto set 10 my hand thisu27th day of July, 1911.

- CHARLES P. STEINMETZ.

.V Vitnesses: i

BENJAMIN B. HULL; HELEN ORFORD. 

